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3 years ago

Who can help and explain these 2 questions

Mathematics

1 answer:

Dominik [7]3 years ago

6 0

Coefficients are added together because they are like terms, this can be proven with the distributive property. For example, x(2x+x)=2x^2+x^2=3x^2.

The commutative property of addition and the associative property demonstrate this.

The word "commutative" comes from "commute" or "move around", so the Commutative Property<span> is the one that refers to moving values around.
</span>
The associative property<span> states that you can add or multiply regardless of how the numbers are grouped. </span>

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What is the answer to this equation?

Bezzdna [24]

19c is the correct answer

6 0

3 years ago

39x38 multiply using partial prodcuts

yKpoI14uk [10]

39 x 10
= 390

39 x 40 (390 x 4)
= 1,560

39 x 2
= 78

1,560 - 78
= 1,482

ANSWER: 1,482

4 0

3 years ago

Find the inverse of the following matrix without using a calculator 1-1 2 -3 2 1 0 4 - 25

Artist 52 [7]

Answer:

18 -(17/3) (5/3)

25 (25/3) (7/3)

4 (4/3) (1/3)

Step-by-step explanation:

You can solve this problem by using the Gauss-Jordan method.

You have the original matrix and then the Identity matrix.

So:

Original Identity

1 -1 2 1 0 0

-3 2 1 0 1 0

0 4 -25 0 0 1

By the Gauss-Jordan method, in the original place you will have the identity and in the place that the identity currently is you will have the inverse matrix:

So, let's start by setting the first row element to 0 in the second and the third line.

The first row element of the third line is already at zero, so no changes there. In the second line, we need to do:

L2 = L2 + 3L1

So now we have the following matrixes.

1 -1 2 | 1 0 0

0 -1 7 | 3 1 0

0 4 -25 | 0 0 1

Now we need the element in the second line, second row to be 1. So we do:

L2 = -L2

1 -1 2 | 1 0 0

0 1 -7 | -3 -1 0

0 4 -25 | 0 0 1

Now, in the second row, we need to make the elements at the first and third line being zero. So, we have the following operations:

L1 = L1 + L2

L3 = L3 - 4L2

Now our matrixes are:

1 0 -5 | -2 -1 0

0 1 -7 | -3 -1 0

0 0 3 | 12 4 1

Now we need the element in the third line, third row being one. So we do:

L3 = -L3

1 0 -5 | -2 -1 0

0 1 -7 | -3 -1 0

0 0 1 | 4 (4/3) (1/3)

Now, in the third row, we need the elements in the first and second line being zero. So we do:

L1 = L1 + 5L3

L2 = L2 + 7L3

So we have:

1 0 0 | 18 -(17/3) (5/3)

0 1 0 | 25 (25/3) (7/3)

0 0 1 | 4 (4/3) (1/3)

So the inverse matrix is:

18 -(17/3) (5/3)

25 (25/3) (7/3)

4 (4/3) (1/3)

4 0

3 years ago

When Alice spends the day with the babysitter, there is a 0.6 probability that she turns on the TV and watches a show. Her littl

slava [35]

Answer:

a) There is a 48% probability that both Alice and Betty watch TV tomorrow.

b) There is a 48% probability that Betty watches TV tomorrow.

c) There is a 12% probability that only Alice watches TV tomorrow.

Step-by-step explanation:

We have these following probabilities:

A 60% probability that Alice watches TV.

If Alice watches TV, an 80% probability Betty watches TV.

If Alice does not watch TV, a 0% probability that Betty watches TV, since she cannot turn the TV on by herself.

a) What is the probability that both Alice and Betty watch TV tomorrow?

Alice watches 60% of the time. Betty watches in 80% of the time Alice watches. So:

$P = 0.6*0.8 = 0.48$

There is a 48% probability that both Alice and Betty watch TV tomorrow.

b) What is the probability that Betty watches TV tomorrow?

Since Betty only watches when Alice watches(80% of the time), this probability is the same as the probability of both of them watching. So

$P = 0.6*0.8 = 0.48$

There is a 48% probability that Betty watches TV tomorrow.

c) What is the probability that only Alice watches TV tomorrow?

There is a 60% probability that Alice watches TV tomorrow. If she watches, there is an 80% probability that Betty watches and a 20% probability she does not watch.

$P = 0.6*0.2 = 0.12$

There is a 12% probability that only Alice watches TV tomorrow.

7 0

3 years ago

A bag contains:

masya89 [10]

Answer: 2 out of 20=2/20 but simplified 1/10 for trying to get a green marble.

5 0

3 years ago